A site to exchange benefits is really a good idea. Yet no one has posted much beyond what is widely known.

Useful unformation would be tidbits as for example:

Centurion holders get free access to the executive lounges in Hilton hotels, ie. free breakfast etc. This is an advantage particularly in German Hiltons as the executive rooms are not different whatsoever than the regular rooms. So you get the exact services while paying less for it.

This has saved me EUR 107 per night

I see the centurion essentially as a tool to get more while paying less.